This invention relates to a process for the manufacture of a square bottom bag having a flap or patch to overlie the bag bottom so as to minimize seepage and leakage from the bag through the bottom.
Square bottom or S.O.S. bags when opened have a squared or flat bottom. Moreover, when such bags are placed on a flat surface they tend to stand erect and are self supporting. These bags can be easy to load with items such as grocery items or restaurant items and have become increasingly popular.
The square bottom is formed by folding the bag ends which are in a sense extensions of the front, back and side walls. Various flaps and gussets are formed and folded so as to form the bottom. The two side wall extensions are folded inwardly and form gussets and parallel spaced edges which extend between the front and back walls. Liquids or granular materials may leak or seep from the bag through the bottom at these edges. Thus it has been proposed to fabricate square bottom bags with an internal flap which overlies the bottom so as to minimize seepage or leakage. See, for example, laid-open Canadian patent application, Serial No. 2,064,181-9 filed Mar. 26, 1992.
That laid-open application discloses a separate flap that is applied to the inside of the bag and glue spots on the bottom, particularly between the parallel and spaced edges, to draw the flap down onto the bottom. But it has been found to be desirable to improve upon this structure. especially in connection with multi-ply square bottom bags.
Thus, it is an object of this invention to provide a process for manufacturing multi-ply bags with an internal bottom protecting flap or flaps.
It is another object to provide improvements to such a process that can be adapted to the standard process.
These and other objects of this invention will become apparent from the following disclosure and appended claims.